a7a7933e03
Under certain conditions a stage-view update does not trigger a kms update. In such cases we still want the next update to run within the same refresh cycle, as otherwise we'd waste the remaining time in the current one. At the same time we currently use the `after-update` signal for Wayland frame events, which again may result in more "empty" updates - creating an unthrottled feedback loop. This can trigger excessive load both in the compositor as well as in clients. Introduce a new GSource that is dispatched once per refresh cycle at maximum per stage view and use it to emit frame events. Do so by computing the time from when on we can be sure that an update resulting from a client commit would certainly get scheduled to the next refresh cycle. Note: this only works on the native backend. Given that chances are small that we hit the corresponding issue on e.g. the nested backend, stick to the previous behavior there for now. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2823>
Mutter
Mutter is a Wayland display server and X11 window manager and compositor library.
When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland.
When used on top of Xorg it acts as a X11 window manager and compositing manager.
It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.
Internally it uses a fork of Cogl, a hardware acceleration abstraction library used to simplify usage of OpenGL pipelines, as well as a fork of Clutter, a scene graph and user interface toolkit.
Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS's window manager. It can also be run standalone, using the command "mutter", but just running plain mutter is only intended for debugging purposes.
Contributing
To contribute, open merge requests at https://gitlab.gnome.org/GNOME/mutter.
It can be useful to look at the documentation available at the Wiki.
The API documentation is available at:
- Meta: https://gnome.pages.gitlab.gnome.org/mutter/meta/
- Clutter: https://gnome.pages.gitlab.gnome.org/mutter/clutter/
- Cally: https://gnome.pages.gitlab.gnome.org/mutter/cally/
- Cogl: https://gnome.pages.gitlab.gnome.org/mutter/cogl/
- CoglPango: https://gnome.pages.gitlab.gnome.org/mutter/cogl-pango/
Coding style and conventions
See HACKING.md.
Git messages
Commit messages should follow the GNOME commit message
guidelines. We require an URL
to either an issue or a merge request in each commit. Try to always prefix
commit subjects with a relevant topic, such as compositor: or
clutter/actor:, and it's always better to write too much in the commit
message body than too little.
If a commit fixes an issue and that issue should be closed, add URL to it in
the bottom of the commit message and prefix with Closes:.
Do not add any Part-of: line, as that will be handled automatically when
merging.
The Fixes tag
If a commit fixes a regression caused by a particular commit, it can be marked
with the Fixes: tag. To produce such a tag, use
git show -s --pretty='format:Fixes: %h (\"%s\")' <COMMIT>
or create an alias
git config --global alias.fixes "show -s --pretty='format:Fixes: %h (\"%s\")'"
and then use
git fixes <COMMIT>
Example
compositor: Also consider dark matter when calculating paint volume
Ignoring dark matter when calculating the paint volume missed the case where
compositing happens in complete vacuum.
Fixes: 123abc123ab ("compositor: Calculate paint volume ourselves")
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1234
Default branch
The default development branch is main. If you still have a local
checkout under the old name, use:
git checkout master
git branch -m master main
git fetch
git branch --unset-upstream
git branch -u origin/main
git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.